This invention relates generally to safety apparatus and more particularly to systems for location on the roof of a building or other structure for supporting an object or person therefrom.
It has become a common practice to utilize equipment mounted on the roof of a structure to suspend a person or an object, e.g., scaffolding, therefrom to enable a person to work on the exterior of the building, e.g., wash the building's windows. Many types of support equipment have been used to date. Some types of equipment are arranged to be permanently, stationarily mounted on the roof, see for example, U.S. Pat. No. 4,296,905 (Powell). Other types while being permanently mounted are nevertheless moveable along the roof to facilitate their use, see for example, U.S. Pat. Nos. 3,159,100 (Wylie), 3,854,550 (Shingler), 4,235,055 (Beeche), and 4,454,928 (Marteau et al).
For many applications it has been found desirable to make such support apparatus portable so that it may be readily transported to the roof for use. Typically such portable apparatus are arranged as somewhat compact, wheeled assemblies which include a beam or boom arranged to be extended over the edge of the roof to support a person or object therefrom when the apparatus is in the desired location, e.g., adjacent the edge of the roof. Examples of prior art portable support systems are found in the following U.S. Pat. Nos. 3,608,678 (Blake et al), 4,130,179 (Williams), 4,274,507 (Williams), 4,496,027 (Fisher), 4,801,117 (Take), and 4,817,758 (Gilmore).
While the foregoing portable systems are generally suitable for their intended purposes all suffer from one or more of the following drawbacks, e g., large size, heavy weight, complex construction, expense, difficulty to assemble/disassemble, difficulty to transport to the roof, difficulty to position when on the roof, etc. Accordingly, a need exists for a portable support system which overcomes the disadvantages of the prior art.